This invention relates to decaffeinated coffee and, more particularly, to a process for preparing decaffeinated coffee of improved flavor.
Prior art workers have long been concerned with the adverse effects that commercial decaffeination methods have on the green coffee so treated, causing the finished decaffeinated product to lack, to varying degrees, the flavor and aroma of its undecaffeinated counterpart.
Attempts at preparing decaffeinated coffee which is more nearly akin to undecaffeinated coffee in flavor and aroma have ranged from improving the decaffeination process itself to the overt addition of either natural or synthetic coffee aromas to the decaffeinated product. In general, decaffeination processes involve either "water extraction" or "solvent extraction" methods. Either method may be operated in batch, semi-continuous or continuous fashion. For example, U.S. Pat. No. 2,309,092 to Berry, et al. describes a continuous water decaffeination process wherein caffeine-containing green coffee is countercurrently extracted with a water solution. U.S. Pat. Nos. 3,671,262 and 3,671,263 describe, respectively, batch and continuous decaffeination methods using an organic solvent as the extraction medium.
The particular processes employed and various operating parameters such as temperature, pressure, and flow rate have all been extensively varied and optimized throughout the years in order to minimize the deleterious effect of the caffeine extraction process on the green coffee. However, an important balancing factor which must be considered against these desirable results is the need for achieving efficient extraction of the caffeine from the green coffee material. Thus, for example, while low temperatures may reduce flavor loss in decaffeinated green coffee, it is generally at the expenses of decreased caffeine extraction efficiency.
It is the primary object of this invention to improve the flavor of decaffeinated coffee in the direction of closely matching the flavor of undecaffeinated coffees.
Another object of this invention is to achieve the above flavor improvement without a corresponding decrease in caffeine extraction efficiency.
Yet another object is to achieve these desirable results utilizing a process adaptable to a wide variety of extraction processes and extraction conditions.
These and other objects will become more apparent in light of the specification and claims which follow.